The term in question refers to sexually explicit visual content featuring a character named Android 21 from the Dragon Ball FighterZ video game. This content is produced by fans and distributed online, falling under the umbrella of fan-created erotica. An example would be an animated short or a series of still images depicting the character in sexually suggestive or explicit situations.
The existence and popularity of such content reflect broader trends within online communities and fandoms. Characters, particularly those perceived as attractive or powerful, frequently become subjects of erotic fan art and videos. This activity offers a form of creative expression for fans and caters to specific interests within online communities. The historical context of similar activities dates back to the early days of internet forums and imageboards.